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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /ipc/chromium/src/base/file_descriptor_shuffle.cc
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'ipc/chromium/src/base/file_descriptor_shuffle.cc')
-rw-r--r--ipc/chromium/src/base/file_descriptor_shuffle.cc96
1 files changed, 96 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/file_descriptor_shuffle.cc b/ipc/chromium/src/base/file_descriptor_shuffle.cc
new file mode 100644
index 000000000..13f0c1e70
--- /dev/null
+++ b/ipc/chromium/src/base/file_descriptor_shuffle.cc
@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/file_descriptor_shuffle.h"
+
+#include <errno.h>
+#include <unistd.h>
+
+#include "base/eintr_wrapper.h"
+#include "base/logging.h"
+
+namespace base {
+
+bool PerformInjectiveMultimapDestructive(
+ InjectiveMultimap* m, InjectionDelegate* delegate) {
+ static const size_t kMaxExtraFDs = 16;
+ int extra_fds[kMaxExtraFDs];
+ unsigned next_extra_fd = 0;
+
+ // DANGER: this function may not allocate.
+
+ for (InjectiveMultimap::iterator i = m->begin(); i != m->end(); ++i) {
+ int temp_fd = -1;
+
+ // We DCHECK the injectiveness of the mapping.
+ for (InjectiveMultimap::iterator j = i + 1; j != m->end(); ++j) {
+ DCHECK(i->dest != j->dest) << "Both fd " << i->source
+ << " and " << j->source << " map to " << i->dest;
+ }
+
+ const bool is_identity = i->source == i->dest;
+
+ for (InjectiveMultimap::iterator j = i + 1; j != m->end(); ++j) {
+ if (!is_identity && i->dest == j->source) {
+ if (temp_fd == -1) {
+ if (!delegate->Duplicate(&temp_fd, i->dest))
+ return false;
+ if (next_extra_fd < kMaxExtraFDs) {
+ extra_fds[next_extra_fd++] = temp_fd;
+ } else {
+ DLOG(ERROR) << "PerformInjectiveMultimapDestructive overflowed "
+ << "extra_fds. Leaking file descriptors!";
+ }
+ }
+
+ j->source = temp_fd;
+ j->close = false;
+ }
+
+ if (i->close && i->source == j->dest)
+ i->close = false;
+
+ if (i->close && i->source == j->source) {
+ i->close = false;
+ j->close = true;
+ }
+ }
+
+ if (!is_identity) {
+ if (!delegate->Move(i->source, i->dest))
+ return false;
+ }
+
+ if (!is_identity && i->close)
+ delegate->Close(i->source);
+ }
+
+ for (unsigned i = 0; i < next_extra_fd; i++)
+ delegate->Close(extra_fds[i]);
+
+ return true;
+}
+
+bool PerformInjectiveMultimap(const InjectiveMultimap& m_in,
+ InjectionDelegate* delegate) {
+ InjectiveMultimap m(m_in);
+ return PerformInjectiveMultimapDestructive(&m, delegate);
+}
+
+bool FileDescriptorTableInjection::Duplicate(int* result, int fd) {
+ *result = HANDLE_EINTR(dup(fd));
+ return *result >= 0;
+}
+
+bool FileDescriptorTableInjection::Move(int src, int dest) {
+ return HANDLE_EINTR(dup2(src, dest)) != -1;
+}
+
+void FileDescriptorTableInjection::Close(int fd) {
+ HANDLE_EINTR(close(fd));
+}
+
+} // namespace base